“Condoms remain one of the most used strategies for HIV and STI prevention amongst HIV-negative gay and bi men in Vancouver,” says Dr. Nathan Lachowsky, the study’s leading author and a Research Associate with the BC-CfE. “Condoms were used about half the time, but we did see a slight decrease over the two-year study period that we need to investigate further.”

As part of the BC-CfE’s Momentum Study, gbMSM men were surveyed about their last sexual encounters with up to their five most recent partners. The survey also included questions aimed to determine whether knowledge and awareness of Treatment as Prevention (TasP) affected condom use. TasP is the immediate and universal offer of HIV treatment to those who test positive. On treatment, an individual achieves an undetectable viral load, which makes the chance they will transmit the virus negligible.

Does awareness of HIV treatment outcomes and of Treatment as Prevention affect condom use among HIV-negative gbMSM?

TasP-related factors were not the leading factors affecting condom use. This parallels past research, which found that awareness of TasP was not associated with riskier sex. However, this study found significantly lower odds of condom use were reported by HIV-negative gbMSM who had practiced viral load sorting and who held greater optimism around HIV treatment, or HAART. This may indicate less concern for other forms of STIs; however, it does show awareness of viral load as a function of HIV transmissibility.

The study suggested that efforts to improve sexual altruism (sexual behaviour with the parter’s wellbeing in mind) and discussions about HIV status might help improve condom use. Individuals who felt more responsibility for protecting their partners and the gay community from HIV and STI transmission were more likely to report condom use. “The study confirms what we’ve known in terms of HIV status: if people are aware of their partners’ HIV status—regardless of whether HIV-positive or HIV-negative—they were less likely to use condoms compared with partners of unknown status,” said Dr. Lachowsky.

Condoms were still not used in one third of sexual encounters with a partner of unknown HIV status.

What are some of the most significant factors in the decision to use a condom?

One of the study’s most significant findings, which points to the need for further research, is the link between substance use and non-condom use. In particular, crystal meth led to very low rates of condom use.

“We need to do more research to discover how to intervene in areas such as substance use, in particular around the use of crystal meth,” said Dr. Lachowsky. “We also found that negatively-motivated substance use in general leads to reduced condom use. There could be a context in which guys meet that produces some anxiety and leads to substance use. This highlights the important links between mental health, substance use and sex.”

How do relationships factor in?

Relationship factors were most predictive of condom use, essentially how well the individual knew their sexual partner and if they planned to have sex with them again. Condoms were used less commonly with longer term partners and those they planned to see again. Any surprising findings? Men who engaged in both insertive and receptive anal sex in the same sexual encounter with a partner were less likely to use condoms. Higher income was associated with reduced condom use. And, in contradiction to stereotypes about risky behaviour among youth, condoms were used 62% of the time in the last sexual encounter among those aged 18-29. This is compared with 26% of the time among those aged 30-44 and 12% of the time among those aged 45 and older.

These findings, which highlight new important trends and factors, illustrate the importance of ongoing research on STI and HIV prevention methods. This information helps better inform future practices. A previous Momentum Study found that gbMSM with more sexual partners were less likely to engage in risky sexual behaviours.